This circuit was found in the July 1988 issue of Radio Electronics magazine. It makes use of an operational transconductance amplifier (OTA) still in use today.
According to the author of this project, from a documentation on espionage from the 1980s, this...
This circuit suggested by Siemens can provide time intervals for triggering values that are given...
This circuit generates a good-intensity 1 kHz rectangular signal. The circuit is from Electronics Now...